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#ifndef _I386_CHECKSUM_H
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#define _I386_CHECKSUM_H
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#include <linux/in6.h>
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/*
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 * computes the checksum of a memory block at buff, length len,
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 * and adds in "sum" (32-bit)
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 *
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 * returns a 32-bit number suitable for feeding into itself
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 * or csum_tcpudp_magic
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 *
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 * this function must be called with even lengths, except
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 * for the last fragment, which may be odd
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 *
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 * it's best to have buff aligned on a 32-bit boundary
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 */
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asmlinkage unsigned int csum_partial(const unsigned char * buff, int len, unsigned int sum);
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/*
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 * the same as csum_partial, but copies from src while it
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 * checksums, and handles user-space pointer exceptions correctly, when needed.
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 *
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 * here even more important to align src and dst on a 32-bit (or even
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 * better 64-bit) boundary
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 */
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asmlinkage unsigned int csum_partial_copy_generic( const char *src, char *dst, int len, int sum,
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                                                   int *src_err_ptr, int *dst_err_ptr);
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/*
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 *      Note: when you get a NULL pointer exception here this means someone
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 *      passed in an incorrect kernel address to one of these functions.
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 *
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 *      If you use these functions directly please don't forget the
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 *      verify_area().
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 */
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static __inline__
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unsigned int csum_partial_copy_nocheck ( const char *src, char *dst,
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                                        int len, int sum)
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{
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        return csum_partial_copy_generic ( src, dst, len, sum, NULL, NULL);
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}
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static __inline__
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unsigned int csum_partial_copy_from_user ( const char *src, char *dst,
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                                                int len, int sum, int *err_ptr)
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{
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        return csum_partial_copy_generic ( src, dst, len, sum, err_ptr, NULL);
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}
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/*
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 *      This is a version of ip_compute_csum() optimized for IP headers,
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 *      which always checksum on 4 octet boundaries.
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 *
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 *      By Jorge Cwik <jorge@laser.satlink.net>, adapted for linux by
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 *      Arnt Gulbrandsen.
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 */
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static inline unsigned short ip_fast_csum(unsigned char * iph,
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                                          unsigned int ihl)
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{
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        unsigned int sum;
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        __asm__ __volatile__(
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            "movl (%1), %0      ;\n"
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            "subl $4, %2        ;\n"
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            "jbe 2f             ;\n"
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            "addl 4(%1), %0     ;\n"
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            "adcl 8(%1), %0     ;\n"
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            "adcl 12(%1), %0    ;\n"
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"1:         adcl 16(%1), %0     ;\n"
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            "lea 4(%1), %1      ;\n"
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            "decl %2            ;\n"
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            "jne 1b             ;\n"
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            "adcl $0, %0        ;\n"
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            "movl %0, %2        ;\n"
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            "shrl $16, %0       ;\n"
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            "addw %w2, %w0      ;\n"
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            "adcl $0, %0        ;\n"
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            "notl %0            ;\n"
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"2:                             ;\n"
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        /* Since the input registers which are loaded with iph and ipl
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           are modified, we must also specify them as outputs, or gcc
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           will assume they contain their original values. */
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        : "=r" (sum), "=r" (iph), "=r" (ihl)
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        : "1" (iph), "2" (ihl)
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        : "memory");
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        return(sum);
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}
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/*
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 *      Fold a partial checksum
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 */
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static inline unsigned int csum_fold(unsigned int sum)
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{
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        __asm__(
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                "addl %1, %0            ;\n"
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                "adcl $0xffff, %0       ;\n"
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                : "=r" (sum)
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                : "r" (sum << 16), "0" (sum & 0xffff0000)
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        );
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        return (~sum) >> 16;
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}
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static inline unsigned long csum_tcpudp_nofold(unsigned long saddr,
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                                                   unsigned long daddr,
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                                                   unsigned short len,
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                                                   unsigned short proto,
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                                                   unsigned int sum)
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{
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    __asm__(
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        "addl %1, %0    ;\n"
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        "adcl %2, %0    ;\n"
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        "adcl %3, %0    ;\n"
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        "adcl $0, %0    ;\n"
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        : "=r" (sum)
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        : "g" (daddr), "g"(saddr), "g"((ntohs(len)<<16)+proto*256), "0"(sum));
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    return sum;
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}
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/*
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 * computes the checksum of the TCP/UDP pseudo-header
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 * returns a 16-bit checksum, already complemented
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 */
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static inline unsigned short int csum_tcpudp_magic(unsigned long saddr,
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                                                   unsigned long daddr,
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                                                   unsigned short len,
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                                                   unsigned short proto,
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                                                   unsigned int sum)
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{
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        return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
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}
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/*
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 * this routine is used for miscellaneous IP-like checksums, mainly
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 * in icmp.c
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 */
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static inline unsigned short ip_compute_csum(unsigned char * buff, int len)
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{
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    return csum_fold (csum_partial(buff, len, 0));
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}
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#define _HAVE_ARCH_IPV6_CSUM
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static __inline__ unsigned short int csum_ipv6_magic(struct in6_addr *saddr,
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                                                     struct in6_addr *daddr,
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                                                     __u32 len,
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                                                     unsigned short proto,
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                                                     unsigned int sum)
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{
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        __asm__(
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                "addl 0(%1), %0         ;\n"
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                "adcl 4(%1), %0         ;\n"
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                "adcl 8(%1), %0         ;\n"
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                "adcl 12(%1), %0        ;\n"
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                "adcl 0(%2), %0         ;\n"
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                "adcl 4(%2), %0         ;\n"
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                "adcl 8(%2), %0         ;\n"
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                "adcl 12(%2), %0        ;\n"
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                "adcl %3, %0            ;\n"
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                "adcl %4, %0            ;\n"
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                "adcl $0, %0            ;\n"
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                : "=&r" (sum)
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                : "r" (saddr), "r" (daddr),
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                  "r"(htonl(len)), "r"(htonl(proto)), "0"(sum));
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        return csum_fold(sum);
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}
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/*
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 *      Copy and checksum to user
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 */
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#define HAVE_CSUM_COPY_USER
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static __inline__ unsigned int csum_and_copy_to_user(const char *src, char *dst,
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                                    int len, int sum, int *err_ptr)
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{
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        if (access_ok(VERIFY_WRITE, dst, len))
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                return csum_partial_copy_generic(src, dst, len, sum, NULL, err_ptr);
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        if (len)
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                *err_ptr = -EFAULT;
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        return -1; /* invalid checksum */
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}
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#endif